Topband: New Solar Cycle Forecast

Bill Tippett btippett at
Tue Mar 7 21:06:25 EST 2006

         This forecast is at odds with one published last
spring which predicted a lower than normal cycle for
the next one.  Time will tell!

                                 73,  Bill  W4ZV

"New Model Predicts Timing and Intensity of Solar Storms

Sunspots have long been known to appear and disappear from the sun's 
surface. The powerful magnetic fields that block light from escaping 
the sun's interior burst into being on the surface and slowly fade as 
they migrate toward the poles. A new model may help predict the 
intensity and timing of such solar outbursts as well as reveal the 
underlying mechanism of the sunspot cycle.

Mausumi Dikpati and her colleagues at the National Center for 
Atmospheric Research in Boulder, Colo., used new observations of the 
sun's interior and new computer simulations to model the flow of 
plasma, or electrically charged gas, that carry the sunspots like a 
conveyor belt until they become powerful enough to burst free and 
erupt on the sun's surface. As the spots weaken, the belt then slowly 
carries them toward the poles and, ultimately, back into the sun's 
core where they become the foundation of the next sunspot cycle. "The 
remnants from the past three cycles combine to produce a certain seed 
for the present cycle," Dikpati explains. "We now know that it takes 
two cycles to fill half the belt with magnetic field and another two 
cycles to fill the other half. Because of this, the next solar cycle 
depends on characteristics from as far back as 40 years 
previously--the sun has a magnetic memory."

This model proved more than 98 percent effective in predicting the 
relative strength and duration of the past eight solar storm cycles, 
which last for roughly 11 years, according to the team's report in 
the current issue of Geophysical Research Letters. And it calls for 
the next cycle--so-called cycle 24--to be 30 to 50 percent stronger 
than the present one. Solar outbursts have effects on everything from 
satellites to the electrical grid here on Earth and predicting such 
storms is a continuing effort for NASA, NOAA and other government and 
scientific groups.

The relatively new science of solar weather prediction remains 
argumentative, however, not unlike terrestrial meteorology. Another 
model predicted that cycle 24 would be weaker than recent cycles, but 
the present model's accuracy in predicting past events and 
scientists' deeper understanding of the underlying solar physics may 
give it an edge, according to David Hathaway, a solar astronomer at 
NASA's Marshall Space Flight Center. But even he disagrees with some 
of the model's findings. It predicts that the next cycle will be 
delayed until late 2007 or early 2008. "We have found that large 
cycles usually start early," he says. "We think the next cycle will 
start late this year or early next year. We're just anxiously 
awaiting the appearance of those first spots." --David Biello"


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